Antenna device for near-field illumination of the skin by millimetre waves

1. Antenna device for near-field illumination of the skin by millimeter waves, wherein said device is configured to superimpose a plurality of electromagnetic modes in the near field using a multilayer structure comprising, according to a vertical direction of stacking: a first power supply layer comprising at least a first dielectric on an application-specific integrated circuit and on a first lower part of a metallic DC power supply circuit, a second DC power supply layer, superimposed on the first power supply layer in the vertical stacking direction, and comprising a second upper part of a metallic DC power supply circuit, a third layer, superimposed on the second supply layer in the vertical stacking direction, and comprising a second dielectric on a metal plane, a fourth layer comprising at least one planar radiating element of said antenna device, the fourth layer is superimposed on the third layer in the vertical stacking direction, the metal plane of the third layer acts as a ground plane of the radiating element, and a fifth layer, superimposed on the fourth layer in the vertical stacking direction, and comprising a radome capable of separating said at least one radiating element from the skin, the antenna device further comprising at least one feed line extending vertically from the first layer to the fourth layer.

2. The antenna device according to claim 1, wherein the electromagnetic modes capable of being superimposed are cylindrical modes.

3. The antenna device according to claim 2, wherein the electromagnetic modes capable of being superimposed, further comprise cavity modes capable of being excited by adding at least one metal cavity within the multilayer structure.

4. The antenna device according to claim 1, wherein the said at least one planar radiating element is a fleeing wave radiating element corresponding to at least one patch with annular slot(s), or at least one patch with continuous transverse stubs.

5. The antenna device according to claim 1, wherein the third layer comprises at least one transverse row of metal via(s) defined by the vertical stacking direction and a transverse direction perpendicular to the vertical stacking direction, said at least one transverse row of metal via(s) extending vertically from the metal ground plane of the third layer to the plane of the fourth layer comprising said at least one planar radiating element.

6. The antenna device according to claim 5, wherein the at least one planar radiating element is a fleeing wave radiating element corresponding to at least one patch with annular slot(s), the third layer comprising, on either side of said at least one patch with annular slot(s) at least one transverse row of metal via(s) extending vertically from the metal ground plane to the plane of the fourth layer comprising said at least one patch with annular slot(s), said at least one feed line extending vertically from the centre of the first supply layer to the centre of said at least one patch with annular slot(s).

7. The antenna device according to claim 5, wherein the at least one planar radiating element is a fleeing wave radiating element corresponding to at least one patch with continuous transverse stubs, the third layer comprising, on each side of at least one patch with continuous transverse stubs, at least one transverse row of metal via(s) extending vertically from the metal ground plane to the plane of the fourth layer comprising said at least one patch with continuous transverse stubs, said at least one supply line extending vertically from the centre of the first layer to the centre of the fourth layer comprising said at least one patch with continuous transverse stubs, slots of said at least one patch with continuous transverse stubs being distributed symmetrically on either side of the feed point supplied by the feed line within the fourth layer.

8. The antenna device according to claim 5, wherein the at least one planar radiating element is a fleeing wave radiating element corresponding to at least one patch with continuous transverse stubs, the third layer comprising, located substantially near a first transverse end of said third layer, at least one transverse row of metal via(s) extending vertically from the metallic ground plane to the plane of the fourth layer comprising said at least one patch with continuous transverse stubs, said at least one supply line, extending vertically from the first layer to the fourth layer by being substantially located at a level of a second transverse end, of the third layer, parallel and opposite to the first transverse end of said third layer located substantially close to said at least one transverse row of metal via(s), said at least one supply line being able to excite a first transverse magnetic mode of said at least one patch with continuous transverse stubs.

9. The antenna device according to claim 8, further comprising between said at least one transverse row of metal via(s) and said at least one feed line, at least two other metal vias extending vertically from the metal ground plane to the plane of the fourth layer comprising at least one patch with continuous transverse stubs.

10. The antenna device according to claim 5, wherein the at least one planar radiating element is a fleeing wave radiating element corresponding to at least one patch with continuous transverse stubs, the third layer comprising, located substantially near a first transverse end of said third layer, at least one transverse row of metal via(s) extending vertically from the metallic ground plane to the plane of the fourth layer comprising said at least one patch with continuous transverse stubs, and comprising at least two longitudinal waveguides obtained by inserting within the third layer at least one other longitudinal perpendicular row of metal via(s), in a longitudinal direction, to both said at least one transverse row of metal via(s) and to the metal ground plane, said at least one other longitudinal row of metal via(s) extending vertically from the metallic ground plane to the plane of the fourth layer with at least one patch with continuous transverse stubs.

11. The antenna device according to claim 10, wherein said at least one longitudinal row of metal via(s) extends longitudinally from said at least one transverse row of metal via(s) and beyond the last slot of said at least one patch with continuous transverse stubs while stopping at a distance from a second transverse end, of the third layer, parallel and opposite the first end of this third layer located substantially close to the at least one transverse row of metal via(s), said at least one supply line, extending vertically from the first layer to the fourth layer by being located longitudinally between: the end of said at least one longitudinal row of metal via(s) opposite to said at least one transverse row of metal via(s), and the second transverse end of the third layer, parallel and opposite to the first transverse end of said third layer located substantially close to said at least one transverse row of metal via(s).

12. The antenna device according to claim 11, wherein said at least one longitudinal row of metal via(s) extends longitudinally from at least one transverse row of metal via(s) and beyond the second transverse end, of the third layer, parallel and opposite to the first transverse end of said third layer located substantially close to said at least one transverse row of metal via(s), the antenna device then comprising at least two supply lines, extending vertically from the first layer to the fourth layer and being located transversely on either side of at least a longitudinal row of metal via(s).

13. An antenna device according to claim 1, wherein the radome is configured to be a modulated dielectric blanket.